diff --git a/dgif_lib.c b/dgif_lib.c
index cbcf23f..15dee84 100644
--- a/dgif_lib.c
+++ b/dgif_lib.c
@@ -57,7 +57,7 @@ GifFileType *DGifOpenFileName(const char *FileName, int *Error) {
 	int FileHandle;
 	GifFileType *GifFile;
 
-	if ((FileHandle = open(FileName, O_RDONLY)) == -1) {
+	if ((FileHandle = _open(FileName, O_RDONLY)) == -1) {
 		if (Error != NULL) {
 			*Error = D_GIF_ERR_OPEN_FAILED;
 		}
@@ -84,7 +84,7 @@ GifFileType *DGifOpenFileHandle(int FileHandle, int *Error) {
 		if (Error != NULL) {
 			*Error = D_GIF_ERR_NOT_ENOUGH_MEM;
 		}
-		(void)close(FileHandle);
+		(void)_close(FileHandle);
 		return NULL;
 	}
 
@@ -99,7 +99,7 @@ GifFileType *DGifOpenFileHandle(int FileHandle, int *Error) {
 		if (Error != NULL) {
 			*Error = D_GIF_ERR_NOT_ENOUGH_MEM;
 		}
-		(void)close(FileHandle);
+		(void)_close(FileHandle);
 		free((char *)GifFile);
 		return NULL;
 	}
@@ -110,7 +110,7 @@ GifFileType *DGifOpenFileHandle(int FileHandle, int *Error) {
 	_setmode(FileHandle, O_BINARY); /* Make sure it is in binary mode. */
 #endif                                  /* _WIN32 */
 
-	f = fdopen(FileHandle, "rb"); /* Make it into a stream: */
+	f = _fdopen(FileHandle, "rb"); /* Make it into a stream: */
 
 	/*@-mustfreeonly@*/
 	GifFile->Private = (void *)Private;
diff --git a/egif_lib.c b/egif_lib.c
index 1526868..6644eed 100644
--- a/egif_lib.c
+++ b/egif_lib.c
@@ -64,10 +64,10 @@ GifFileType *EGifOpenFileName(const char *FileName, const bool TestExistence,
 	GifFileType *GifFile;
 
 	if (TestExistence) {
-		FileHandle = open(FileName, O_WRONLY | O_CREAT | O_EXCL,
+		FileHandle = _open(FileName, O_WRONLY | O_CREAT | O_EXCL,
 		                  S_IREAD | S_IWRITE);
 	} else {
-		FileHandle = open(FileName, O_WRONLY | O_CREAT | O_TRUNC,
+		FileHandle = _open(FileName, O_WRONLY | O_CREAT | O_TRUNC,
 		                  S_IREAD | S_IWRITE);
 	}
 
@@ -79,7 +79,7 @@ GifFileType *EGifOpenFileName(const char *FileName, const bool TestExistence,
 	}
 	GifFile = EGifOpenFileHandle(FileHandle, Error);
 	if (GifFile == (GifFileType *)NULL) {
-		(void)close(FileHandle);
+		(void)_close(FileHandle);
 	}
 	return GifFile;
 }
@@ -125,7 +125,7 @@ GifFileType *EGifOpenFileHandle(const int FileHandle, int *Error) {
 	_setmode(FileHandle, O_BINARY); /* Make sure it is in binary mode. */
 #endif                                  /* _WIN32 */
 
-	f = fdopen(FileHandle, "wb"); /* Make it into a stream: */
+	f = _fdopen(FileHandle, "wb"); /* Make it into a stream: */
 
 	GifFile->Private = (void *)Private;
 	Private->FileHandle = FileHandle;
diff --git a/gif_font.c b/gif_font.c
index 75f9731..c215795 100644
--- a/gif_font.c
+++ b/gif_font.c
@@ -200,6 +200,9 @@ void GifDrawRectangle(SavedImage *Image, const int x, const int y, const int w,
 	}
 }
 
+#ifdef _MSC_VER
+#  define strtok_r strtok_s
+#endif
 void GifDrawBoxedText8x8(SavedImage *Image, const int x, const int y,
                          const char *legend, const int border, const int bg,
                          const int fg) {